Hydrogen Water Improves Gut Health and Bowel Function in New Study
- Authors
- Yoshinori Tanaka, Masataka Kiuchi, Yasuki Higashimura, Yuji Naito, Katsuhiro Koyama
- Journal
- Medical Gas Research
- Year
- 2021
- DOI
- 10.4103/2045-9912.318858
- Study Type
- Human
- Outcome
- Positive
- Peer Reviewed
- Yes
- Country
- Japan
- Health Condition
- Constipation
- Body System
- Digestive
TL;DR
Drinking alkaline electrolyzed water (AEW) may improve stool consistency and increase beneficial gut bacteria without significantly altering the overall gut microbiota.
Key Finding
Drinking hydrogen-dissolved alkaline electrolyzed water for 2 weeks increased Bifidobacterium levels and improved stool consistency toward normal values in a double-blind randomized trial.
Summary
In a 2-week study, people who drank hydrogen-rich alkaline water daily showed an increase in Bifidobacterium (a type of beneficial bacteria in the gut) compared to those who drank regular purified water. The group drinking the special water also had stool consistency that shifted toward what doctors consider normal. However, the water did not make major overall changes to the types of bacteria living in the gut.
Practical Takeaway
This small human study suggests hydrogen-rich alkaline water may selectively increase beneficial gut bacteria and normalize bowel function, though the overall impact on gut microbiota was modest. The 2-week duration is quite short, so it's unclear whether these changes persist longer or translate to meaningful health benefits. More research with larger groups and longer follow-up would be needed to determine practical value.
Abstract
A relationship between Bifidobacterium and defecation has previously been reported. Our hypothesis on the effectiveness of alkaline electrolyzed water (AEW) proposes that ingestion of AEW, considered possessing antioxidative properties, increases the number of Bifidobacteria and improves stool hardness and gastrointestinal symptoms. A double-blind, randomized study was conducted to evaluate the connection between stool consistency and change in gut microbiota composition induced by drinking hydrogen-dissolved AEW. The participants drank 500 mL of purified tap water or AEW every day for 2 weeks. In this study, drinking AEW did not drastically change gut microbiota, but it appeared to act on a specific bacterial species. Drinking AEW was confirmed to cause an increase in Bifidobacterium. The AEW group also saw stool consistency significantly converge to Bristol stool scale Type 4 ('normal'). Therefore, it is highly likely that the gut microbiota will be changed by drinking AEW. This study was retrospectively registered in University Hospital Medical Information Network (UMIN) Clinical Trials Registry (UMIN ID: UMIN000039507) on February 18, 2020, and was approved by the Ethics Committee of University of Yamanashi (approval No. H30-25) on January 9, 2018.